The invention relates to apparatus for applying viscous materials to a surface or other work according to a predetermined pattern. A typical application relates to electronic circuit boards having printed circuits and components mounted thereon. A typical process for securing the leads of discrete components, such as resistor, capacitors and semi-conductor units, to the printed conductors comprises flow or dip soldering. A circuit board designed to be soldered in that manner would ordinarily have the discrete components mounted on one side of the board with their leads feeding through holes or eylets associated with the opposite side of the board, the solder being deposited to accomplish electrical connections where desired.
In the typical circuit board as aforementioned, there are always areas exposed to the soldering process which must be protected from unintentional solder connection, hence the practice of masking those areas has become conventional. Obviously such masking may be applied manually, although that approach is tedious and time-consuming and therefore economically disadvantageous.